Zantac and Pepcid are now essentially the same medication. Today’s Zantac 360 contains famotidine, which is the exact same active ingredient found in Pepcid AC, sold in the same strengths. This wasn’t always the case. The original Zantac contained a completely different drug called ranitidine, which was pulled from the market in 2020 over contamination concerns. The Zantac brand was then relaunched with famotidine inside, making the two products interchangeable.
Why Zantac Changed Its Formula
The original Zantac used ranitidine as its active ingredient for decades. In April 2020, the FDA requested the removal of all ranitidine products from the U.S. market after discovering they contained a contaminant called NDMA, a substance linked to cancer risk. Testing revealed that NDMA levels in ranitidine increased over time even under normal storage conditions, and rose significantly at higher temperatures, including the kind of heat a product might encounter during shipping or sitting in a medicine cabinet. The older the product, the worse the contamination became.
After the withdrawal, the Zantac brand was reformulated and relaunched as Zantac 360, now built around famotidine instead of ranitidine. Famotidine does not carry the same NDMA contamination risk.
Same Active Ingredient, Same Strengths
Both Zantac 360 and Pepcid AC contain famotidine and are available over the counter in 10 mg and 20 mg tablets. Pepcid AC also comes in a 40 mg tablet. Because the active ingredient is identical, choosing between the two comes down to price, availability, or personal preference. There is no clinical difference between a 20 mg Zantac 360 tablet and a 20 mg Pepcid AC tablet. Generic famotidine, which is typically cheaper than either brand, works the same way.
How Famotidine Works
Famotidine belongs to a class of drugs called H2 blockers. After you eat, your body releases a chemical called histamine that binds to receptors on the cells lining your stomach, triggering acid production. Famotidine blocks those receptors so histamine can’t attach, which reduces the amount of acid your stomach makes. It starts working within about an hour, reaches its peak effect in one to three hours, and a single dose suppresses acid production for 10 to 12 hours.
What These Medications Treat
Famotidine, whether sold as Pepcid or Zantac 360, is used for heartburn, acid indigestion, and gastroesophageal reflux disease (GERD). The prescription-strength version is also approved for stomach and intestinal ulcers, erosive esophagitis caused by GERD, and conditions where the stomach produces far too much acid. For occasional heartburn, the over-the-counter doses are typically sufficient. If you’re using it more than 14 days in a row, that’s worth a conversation with a healthcare provider.
How Famotidine Compares to the Old Ranitidine
If you remember the original Zantac working well for you, the reformulated version should perform at least as well. Research comparing the two drugs found that famotidine is actually more potent at raising stomach pH (meaning it reduces acid more effectively). In one study of critically ill patients, famotidine kept stomach pH above the therapeutic threshold in about 79% of samples, compared to roughly 33% for ranitidine. Famotidine also achieved this with less frequent dosing: twice a day versus three times a day for ranitidine.
Side Effects to Know About
Because both products contain the same drug, they share the same side effect profile. The most common issues are mild: headache, dizziness, constipation, or diarrhea. These tend to be manageable and often resolve on their own.
Serious reactions are uncommon but include hives, skin rash, swelling of the face or throat, and difficulty breathing or swallowing. These are signs of an allergic reaction and need immediate medical attention.
Which One Should You Buy?
If you’re standing in a pharmacy aisle comparing Zantac 360 and Pepcid AC, you’re looking at the same medication in different packaging. Check the milligram strength on the box to make sure you’re getting what you need, then pick whichever costs less. Generic famotidine is widely available and costs a fraction of either brand name. All three options will give you identical heartburn relief.